Two British Chinook helicopters will arrive in northern Pakistan today as international efforts accelerate to rescue thousands of survivors at risk from the impending fierce Himalayan winter.

They will join a third Chinook, flown out from the UK yesterday in a Hercules cargo plane, as part of the frantic efforts to alleviate the suffering of people trapped among the 15,000 mountain settlements yet to receive aid following the earthquake two weeks ago.

Alongside Britain's latest response, Nato will today start deploying up to 1,000 troops from Spain, Italy, Lithuania and elsewhere to help to clear landslides and establish a field hospital. The Chinooks will begin rescuing those marooned in remote settlements or bringing much-needed supplies to cut-off villages.

'Time is against us,' said Jan Vandemoortele, the UN humanitarian coordinator in Islamabad. 'We can buy everything with money, but not time.'

Amid the calls for increased urgency, India announced yesterday it will set up three aid camps by Tuesday along its disputed border with Pakistan. The move will allow Pakistani victims of the earthquake to cross the heavily militarised frontier for medical treatment.

The camps in the earthquake-hit zone of Kashmir will also provide food, water and tents to the victims, allowing Kashmiris on the Pakistan side of Kashmir to cross on foot for the first time since 1948. The move was hailed yesterday as another goodwill gesture between the long-time rivals in the wake of the earthquake two weeks ago, which killed some 80,000 people.

However, there was still anger over allegations that officials from Pakistan were diverting vital relief supplies. Human Rights Watch claimed that tents and other aid were being hoarded by local authorities in Muzaffarabad, the Kashmiri city at the heart of the quake zone.

'Tents are the difference between life and death,' said the group's Asia director, Brad Adams. However, local officials said the New York-based group had got its facts wrong. 'We register the supplies coming through the official channels, and then forward them to the most deserving locations in the affected areas,' said Liaquat Hussain, deputy commissioner of Muzaffarabad.

An estimated 3.3 million people were made homeless by the earthquake. Aid officials estimate that up to 540,00 tents are required, but only 122,00 have been delivered. Aid agency plans to send another 83,000 are just a 'drop in the ocean' said UN official Jesper Lund.

Shelter is just one headache of a growing relief operation that aid workers describe as the most difficult the world has ever faced. Forbidding mountains, freezing weather, chronic supply shortages and lack of outside help could push the death toll far above current estimates of 79,000, they warn.

However, further help is likely to be forthcoming after World Bank chief Paul Wolfowitz said the institution would step up its efforts to help Pakistan. The bank had earlier pledged £16 million in aid to Pakistan.

'The scale of the disaster is so enormous that, frankly, a big part of the effort has to go to figuring what the needs really are,' said Wolfowitz.